Basic research will be conducted into the generation, characterization, transport, delivery, and deposition phenomena of liquid therapeutic aerosols. The first phase of the study will be to investigate the fundamental behavior of therapeutic aerosols over a wide range of variables to generate a better understanding of the method. From such a study should emerge a data base which can be used to prescribe the characteristics of the aerosol and delivery system needed to deposit any drug in the desired lung location. Finally, current aerosol therapy systems will be tested against this data base, to determine their potential to deliver aerosol of the required characteristics to the patient.